Fabricação de catalisadores de PtSn/C modificados com Ni e Ga para a oxidação de etanol

• Ano de defesa: 2016
• Autor(a) principal: Paganoto, Giordano Toscano
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Química; Centro de Ciências Exatas; UFES; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Plasma; Etanol; Vulcan; Printex; Ethanol; Oxidation; Fuel cells; Álcool; Oxidação; Carbono ativado; Células à combustível; Platina; Química; 54
• Link de acesso: http://repositorio.ufes.br/handle/10/7328

In this investigation we studied the influence of the carbon support in the electrocatalytic activity of quaternary catalyst of nominal composition Pt50Sn20Ni25Ga5/C and the effect ofmodification by Ni and Ga on PtSn/C catalysts, synthesized throughthermal decompositionof polymeric precursormethod at 350 °Cforethanolelectrochemical oxidation reactionThe morphological and electrochemical characterizations were made through the dispersiveX-ray energy, Ramanspectroscopy, X-ray diffraction, transmission electron microscopy, cyclic voltammetry, chronoamperometry, chronopotenciometry and electrochemical impedance spectroscopytechniques. TheVulcan XC72, Printex L6, and PlasmaI(G)/I(D) ratio inRaman spectra of carbon indicate that these materials are formedin most by graphite crystallites andVulcan XC72 is slightly less crystallinecomparing to Printex-L6 and Plasma carbons. Morphological characterizations showed no formation of largenanoparticlesagglomeration in catalysts supported on Vulcan XC72 carbon compared withcatalysts supported on Printex-L6 and Plasma. The average particle sizes ranging from 3.6 nm to 7.0 nm. It was identified increasing lattice parameter Pt CFC structure (a = 3.923 Å) at all synthesized catalyst. The catalyst Pt45Sn22Ni21Ga12/CXC72shows higher Pt-massnormalizedcurrent(2.62 Ag-1Pt), lower susceptibility to anodic poisoning and lower charge transfer resistance (245 O) comparing to Pt43Sn24Ni22Ga11/CL6and Pt41Sn24Ni23Ga12/CPlasma. The study quaternary catalysts PtSnNiGa/C supported on Vulcan XC72 carbon forethanol electrochemical oxidation indicates that changing the composition, with up to four metals, is capable of reducing the amount of Pt and increasing the electrocatalytic activity compared to catalysts with high Pt content.